In Switzerland the rules for the low power e-bike states that the power of the motor is "maximum 500w". Does this refer to the continuous power (i.e. motor stamped 500w), or to the peak power (in which case I assume it's Controller Current setting x Volts)...

In the UK it's 250W continuous, and I thought Switzerland were more generous? But a Bafang BA02 500W supplier in europe has suggested that the rules are for PEAK and not CONTINUOUS power. Would make a big difference

But a Bafang BA02 500W supplier in europe has suggested that the rules are for PEAK and not CONTINUOUS power.

If that's for Europe, then it appears to me to be wrong -

EU 2002/24/EC wrote:Cycles with pedal assistance which are equipped with an auxiliary electric motor having a maximum continuous rated power of 0.25 kW, of which the output is progressively reduced and finally cut off as the vehicle reaches a speed of 25km/h (15.5mph) or if the cyclist stops pedaling.

Whatever they think "continuous" means, I think the important word is really "rated". It doesn't call for a power cutoff at 0.25 kW, like it does at 25km/h, you just need a rating. If there isn't any reference to a standard by which this rating is arrived at, then it's up to the manufacturer. If Bafang wants to rate their motors by the maximum power they can support for 1 second, or for 10 hours, it's up to them, but unless they're crazy they'll rate them by sustained output.

It's a fair bet that Switzerland and everyone else takes the same approach, but it's hard to say by just reading the blog articles, like electricbike.com linked above. If the Bafang supplier is communicative, might ask for a reference to the actual Swiss legislation and see what it says.

I go by the motto of being a courteous cyclist. It is like buying a Lamborghini Aventador that no one in their right mind would speed anything over 20 over the speed limit, units dont even matter whether its kph or mph.

Austria, Switzerland, and probably other EU countries as well didn't follow the so called "EU rules" which claim 250W rated continous. We all know that this is a plain stupid regulation which says nothing about max power, and leaves a lot of room for interpretation.

In Austria the limit clearly is 600W max, but it nowhere states if this is net power consumed by the motor, or gross power coming from the battery. So your battery meter can show 700W max and still the motor consumption can be below 600W and therefore still be legal.

That "ingesamt höchstens 0,50 kW" is less explicit than the EU verbiage. By "höchstens" (maximum), it only means that 500W is the highest power that meets the definition, while 250W, 300W etc. are also acceptable. There's no hint of how this value is arrived at, for a given motor. "Ingesamt" (total) means that for example a front and rear hub configuration would be summed up. I'm not saying any of this is what was in their heads when they wrote it, but it's the reasonable interpretation; it would need some work to really address the present question.

All of what you say is true. Of course 0.5kW is the MAXIMUM. 250W is ok as well. But tbh i don't know of any 250W MAX ebike. Every "so called 250W" Bosch or Yamaha motor built in the last year put out spikes of 600-700W. And this is legal. And i assume that it will be legal in Switzerland as well. Wouldn't make sense else.
And sure you can ride 2x 250W max powered motors. This is not forbidden.

True, its the only thing thats measurable, but there needs to be additional information which non are given, even with the UK. Aside from the link I gave previously, the grin tech tour video, adds good info.https://youtu.be/IxB2j-egWcQ?t=677
At time 12:12 is the other piece of info required but none is given.

Your 600W max, is meaningless. A small 200W motor could pull 1200W, might not last long.

No it's not. It's the ONLY thing that's measurable. Add a Watt meter and you will see what the motor pulls.
Something like 250W continous leaves way too much room for interpretation.

What the motor pulls is not the same as what the motor outputs. So while I wouldn't call the 600w or 500w number meaningless, it is a bit fuzzy given the unknown aspect of the motor efficiency and the lack of specificity of how the motor output should be measured. I think that is the point that a few people were trying to make earlier in the thread.

So if you attach a watt meter, you'd probably have to see watt consumption a bit north of 600 watts or maybe even 700 watts before you could be pretty sure that the motor was outputting more than 500 watts of power. This is the fuzzy bit.

No one involved really wants a meaningful parameter. I mean, it wouldn't kill them if there were a well defined, verifiable power rating, but it would make violations more clear-cut, with the evident intention to enforce. This way, there's enough legal basis for the authorities to hassle trouble-makers, but plenty of room for the industry to do what it wants without having to tailor products to a armload of different jurisdictions.

No one involved really wants a meaningful parameter. I mean, it wouldn't kill them if there were a well defined, verifiable power rating, but it would make violations more clear-cut, with the evident intention to enforce. This way, there's enough legal basis for the authorities to hassle trouble-makers, but plenty of room for the industry to do what it wants without having to tailor products to a armload of different jurisdictions.

I think you make a good point about nobody really wanting a meaningful wattage parameter. I get the strong impression that most of this newer legislation is being pushed by manufacturers and that it is some minor side issue for most legislatures. So they really aren't going to a lot of trouble to think through the details. That said, I agree with izeman that setting a motor output limit is less nebulous than a continuous output rating. But I suspect that in the real world of enforcement, speed limits are the numbers that will be used most for enforcement. Unfortunately for law enforcement, many of these speed limits are only for motor assist speeds. This is sensible given that the speeds bicycles can reach on their own with the aid of downward slopes and tailwinds or short bursts of human power. But it then gets complicated for law enforcement.

And all of this gets back to the point made over and over. If your bike looks like a bicycle and you ride pretty much like a bicycle and don't create obvious problems for others, you will probably be left alone in most jurisdictions. As a practical matter for a person riding a home-brew bike, these things are almost always what matters most. The specifics of the law are interesting, but the police who are the first line of enforcement probably don't know them well.

Before I built my ebike, I googled enforcement in the Phoenix area. What I found almost exclusively was that the guys riding ebikes that looked like scooters and especially those who rode such bikes and gas powered bikes on multi-use park paths, were the ones getting hassled by police. The scooter/moped looking devices were actually completely legal. But their designs made them look like something other than a bicycle. Police in most areas seem to use appearance as a major factor in enforcement. Though police in Switzerland are probably more savy than most given the higher level of ebike use and the S-Pedelecs and their plates.

So for the OP, the key is almost surely to look mostly like a bicycle and to not exceed 25 kph. That, or if he wants to exceed 25 kph, go ahead and get licensed for an S-Pedelec. From what I read, the fees aren't that high. If the Swiss laws applied here, that's probably what I'd do.

The Austrian jurisdiction is rather unique in the European context. They actually regulate the maximum power and mean p(max) = I(max) x U(max), and they allow a throttle without PAS.

I read "Switzerland, Austria and other EU countries". Switzerland does not apply EU rules for they are not EU. They allow 500W continuous and even had precedences in court. The Judge always applying p(cont) = p(max) / 2 = I(max) x U(max) / 2.
The precedences taking place to find out whose fault was a crash.

So far, and thanks for all the fish…

The fundamental laws of thermodynamics will place fixed limits on technological innovation and human advancement.

How would you react if I said that I'm not from Guildford after all, but from a small planet somewhere in the vicinity of Betelgeuse?

So why do they then say "500W max"? Strange if you can't even trust those simple law texts.
And if you say p(cont)=p(max)*50% then this would mean 250W cont for Switzerland, and not 500W cont = 1000W max. 1000W max is defined as a special class ...

They have to say it. If they left it out, "with electric motor 500W", you'd need exactly 500W - no more, no less - to meet that standard. When they say "with electric motor 500W max", that allows anything that isn't more than 500W.

And if you say p(cont)=p(max)*50% then this would mean 250W cont for Switzerland, and not 500W cont = 1000W max. 1000W max is defined as a special class ...

"Max" has to be interpreted in context. Here it's in contrast to "cont", so it's clearly the maximum that can at any time be applied to the motor in question. Where used before in the context of all bicycle motors, it's maximum value that qualifies for that category, where value is determined however they choose in order to assign a value to each of those motors.

Hmmm. Strange interpretation in my opinion, but still valid.
All countries use something like max, cont, etc ... So they should have used "maximal 500W kontinuierlich", which unfortunately makes in not clearer either

Just as a general rule here in Switzerland, everything fun is VERBOTEN !

They do verbiet some really weird things. You probably think "helping someone vomit" in the middle is weird - but who wants to do that on tram with a stranger? Right next to it on the left: "not knowing something". Now, this is degrading.

The fundamental laws of thermodynamics will place fixed limits on technological innovation and human advancement.

How would you react if I said that I'm not from Guildford after all, but from a small planet somewhere in the vicinity of Betelgeuse?

Just as a general rule here in Switzerland, everything fun is VERBOTEN !

They do verbiet some really weird things. You probably think "helping someone vomit" in the middle is weird - but who wants to do that on tram with a stranger? Right next to it on the left: "not knowing something". Now, this is degrading.

Yeah and the one behind the post is actually of a Mexican guy with a guitar, so no Mexicans allowed either